When I recently went from the old Outlaw 990 to the 976 I actually forgot that there was an "trigger" cable that went from my 990 to my Outlaw 7125. When I first hooked up the 976 it wouldn't work with my amp. I was not hearing any audio and the light on the 7125 did not turn blue when I turned on the 976 like when I had the 990. Then I noticed the trigger cable attached to my 7125. Strangely when I connected the trigger cable from the 976 to the 7125 it still did not work. I was so happy to see that when I disconnected the trigger from both the 976 and 7125 it works perfectly without the trigger. Can anyone tell me if Loosing something by not using the trigger? I honestly don't know what function the trigger serves.

You will have to turn the trigger in the input setup menu.
So you pick your input and you will see the option to turn on trigger 1 or 2 or both.

That makes sense. Does using the trigger provide any benefits being as my amp works fine without it?

It depends if you have multiple amps.
In my setup I have mono-blocks for my L/R speakers and my Outlaw 7500 runs my center channel and all of the 4 surrounds.
When I am listened to 2 channel with either my turntable or via streaming the 7500 is turned off because it is not needed.
I you are running just one amp then you can just keep doing what you are doing or you can trigger it so when you shut the 976 down it will turn off your amp.
Your choice.

One thing I forgot to add is if you are running multiple subs you should invest in the Mini DSP 2x4 HD and UMIK-1 microphone.
That way you can get your subs dialed in before you start running REW.
If you are only running one sub then all you need it the UMIK-1 which you can order direct from here - https://www.minidsp.com/
There is a very detailed tutorial on the Home Theater Gurus You Tube channel on setting up multiple subs found here - https://www.youtube.com/watch?v=_A6gPCczhuU&t=1522s

@Butchgo Thanks again buddy. That all makes sense. Maybe I will connect it even though I'm only using one amp (outlaw 7125).

It won't hurt anything to do that for sure.

So you have to select “both”? Or 1 & 2?

Im trying to troubleshoot the 976 i sold via text.

Im trying to get super specific on this setting.

I need to know what to select . Is “both” meaning select 1&2 or is there an actual “both”

If he is only triggering 1 amp then just set what ever input he is using to turn on trigger #1 and run the cable from trigger 1 to the amp.
If he is turning on 2 amps then you can either daisy chain a trigger cable from one amp, assuming it has a trigger out jack, to the other or you can run a separate trigger cable to the 2nd amp.
You can set up each input to either use one trigger out or both.
Hope this helps.